Method of treating hydrocarbon oil



March 15, 1938. w. F. MOORE METHOD OF TREATING HYDROCARBON OIL Filed Nov. 28. 1932 NUI..

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ATTORNEY- Patented Mar. 15, 1938 METHOD F TREATING HYDROCARBON OIL William F. Moore, Bayside, N. Y., assigner to Gasoline Products Company, Inc., Newark, N. J., acorporation of Delaware Application November 28, 1932, Serial No.

1 Claim.

This invention relates to methods for converting higher boiling hydrocarbon oils into lower boiling hydrocarbon oils. 'i

It is an object of my invention toprovide an improved process for ther separation cfa/heavy hydrocarbon oil charging stock intov a plurality of fractions and for the-treatment'of these fractions in combination in such manner that vincreased conversion into the desired lower boiling point product results.

According to my invention a' charging stock such as crude oil having a gravity of about thirty-five degrees A. P. I., or any other comparable product is heated to a moderate temperature 151 under superatmospheric pressure and is thereafter introduced into an evaporating chamber wherein Vaporization takes place and an unvaporized residue is formed. Vapors so produced are thenheated to a relatively high cracking temperature and combined with the residue subsequent to the heating of the residue to a moderate cracking temperature. A dehydrogenating agent,`

such as oxygen, air or steam which hasbeen superheated to dissociation temperature, may be o mixed with the combined produ-cts to promote the formation of unsaturates and thecombined products are thereupon introduced into a soaking chamber wherein further conversion and recombination takes place. The soaked products pass into a separating chamber, held under reduced pressure, wherein vapors are evolved and a tar-like residue formed. The vapors are thereafter subjected to partial condensation in a fractionator, and the uncondensed vapors are removed from the fractionator as the final desired product, while the condensate is combined with the vapors first mentioned, prior to the heating thereof. The residue producedin the separator is withdrawn from the process.

'Ihe `above mentioned and further objects and advantages of my invention will be made clear in the following description takeninv conjunction with the accompanying drawing.

In theY drawing reference numeral I indicates a furnace having therein heating coils 2, 3, 4,

and 5, which are sub-jected to heat producedby burners B, 1, and 8.. Nine' (9) indicates an evaporator, III a soaking chamber, II a` separator and I2 a fractionator. Fresh charging stock', such oc." for example as degree A. P. I. M. C. crude, is

forced by pump 30 through heating coil 2 positioned in the convection portion of the furnace, and then through heating coil 3 located in the radiant portion of the furnace. The heated oil products thereafter pass through pipe I3 and re- (Cl. ISG- 48) ducing valve I4 into evaporator 9; The pressure in the heating coil may, for example, be 500 lbs. per square inch and the temperature to which the oil is heated therein may suitably be from'700850 F. preferably in the neighborhood of 750-800 F. These conditions permit heating of the oil with substantially no cracking. The evaporator 9 may be carried under a pressure of 300V lbs. per square inch and this reduction in pressure ofthe heated oil introduced into the evaporator suffices tofvaporize the lighter portions thereof, which may include gasoline,

kerosene and gas oil, leaving a reduced crude residue of about 20 degrees A. P. I. gravity. 'The vapors passoverhead through pipe I5 into a heating coil 4, and thence through injector I6 into `soaking chamber I0. The temperature attained by the oil vapors in coil 4 may be from 950 degrees to 1200 degrees F. or even higher, but ispreferably approximately l050 F., while the pressure on the heated vapors leaving the coil will be relatively lowye. g. 150 pounds per square inch, although a somewhat lower or higher pressure may prevail. The residue from the evaporator is forced either by the pressure in the evaporator, or by pump I1, through heating coil 5 and injector I6, into the soaking chamber IIJ. The temperature attained by the residual oil in the coil 5 is preferably in the neighborhood of 850 F., but a slightly higher or lower temperature could be used Nif desired. The function of the injector I6, which may be ofany well known type, is to combine and thoroughly mix the two streams of heated oil prior to their introduction into the soaking chamber. such as an ordinary chamber may be used instead if desired. The pressure on the residual oil passed through the coil 5 may be made high enough by the actionof pump Il, so that the heated residual oil can assist, through the action of the injector, in raising the pressure of the highly heated vaporous products prior to their introduction into the soaking chamber. A dehydrogenating agent such as oxygen, air or superheated dissociated steam may be introduced through pipe I8 into the injector I 6 and mixed with the oil to promote polymerization and the formation of unsaturated hydrocarbon compounds.

The fractions of the vapors from evaporator 9 which lie in the gasoline boiling range may `be removed in order to prevent the passage thereof through the heating coil 4, and in this event the temperature of the products passing through heating coil 4 may be increased to a value above Other mixing means, I

. through valve line 22.

thatI mentioned hereinbefore, for example to 1500 F. Fractionator 39 which is provided to remove the gasoline boiling range fraction may be rendered active by proper manipulation of valves 40, 4|, 42 and 43. When valve 40 is closed and valves 4I, 42, and 43 are open the products enter the fractionator through pipe 44 and are fractionated therein, the lightest products passing off through line 45 which connects with the pipe I5 leading toy the cracking coils. The heavy condensate is removed from the bottom of the fractionator through line 46 and introduced into pipe I5, while an intermediate cut of products in the gasoline boiling range is removed as a side stream through pipe 41 and is introduced into storage drum 48. Pipe line 49 having valve 50 is provided for by-passing the reflux condensate from pipe 23 around the fractionator 39, when the latter is in use and valve 5| serves to prevent the reux condensate from combining with thevapors from the evaporator when the by-pass line is in use.

The temperature of the combined products entering the soaking chamber will be intermediate that of the heated residual products and that of the heated vapors, the highly heated vapors serving to raise the temperature of the residual products above that which they attain in the furnace. After being soaked in chamber I in which combination of the relatively light vapors and vfixed gases, with the heavy residual products occurs as a result of their unsaturated condition the products are transferred to separator II through a pipe I9 having a reducing valve 20 therein. The

kpressure in the separator H is lower than that of the soaking chamber I0, for example the pressure in the separator may be 50 pounds per square inch. Lighter products in vapor form pass from the separator through conduit 2| into fractionator I2, While a liquid residue is withdrawn In the fractionator the vapors are dephlegmated, a reflux condensate being formed which is removed from the bottom of the fractionator through pipe 23 having pump 24 and ls combined with thevapors in pipe I for heating in the coil 4. A cooling coil 38 is positioned in the top of the fractionator to supply the necessary reiluxing action. The fresh charge may be passed through the coil if desired, in the usual manner. A connection 3I having a valve 32 therein is furnished for permitting a quantity of the reflux condensate from line 23 to be directed into evaporator 9 to control the conditions therein and regulate the proportion of vapors to residue produced by the vaporizing process, as Well as the quality of the residue. By regulating the valve 32, a greater or lesser amount of reflux condensate may be admitted. A pipe line 33 having valve 34 and cooler 35 serves to conduct any desired quantity of cool reflux condensate into the separator to regulate the amount of vapors evolved therein. A Valved by-pass 36 is included for passing hot condensate around the cooler, thereby affording additional flexibility of control. Valved drawoff line 31 aiords a means for diverting from the process certain amounts o f reilux condensate if desired.

Vapors of the desired end point leave the fractionator through conduit and travel through condenser 26 into gas separator 21 wherein fixed gas is drawn off in the usual manner through pipe 28, and the desired final distillate is removed through pipe 29.

The pressures used in the process described hereinbefore may be increased if desired, the proper ratio of pressures being maintained. For example a pressure of Several thousand pounds per square inch may be placed on the fresh charging stock, and in this case the evaporator and soaking chamber should be held at proportionately lower pressures. The pressures on the separator and fractionator may be raised also but generally pressures of from 50-400 pounds per square inch will be found preferable for the separating and fractionating steps.

By separating the crude petroleum charging stock into two portions and treating them as described hereinbefore several desirable results are attained. Among these are the reformation of any gasoline content of the crude petroleum charging Ystock and the contacting of the resulting hot Xed gases and light products with the residue for further conversion and recombination, including polymerization. A further advantage is thatmore extensive cracking of the heavy oil can bel obtained without coke difficulties than would be possible in an externally heated coil alone. The tworportions of the charging stock may also be subjected to individually controlled conditions which are especially Well adapted for theirtreatment.

While I have described a particular embodiment of my invention for the purpose of illustration it vshould be understood that various modifications and adaptations thereof may be made Within the spirit of the invention as set forth in the appended claim.

I claim:

In a process for the treatment of hydrocarbon oil wherein the oil is subjected to a topping operation for the separation of a low-boiling fraction, containing materials within the boiling range of gasoline, from higher boiling residual components, said low-boiling fraction subjected to conversion conditions of elevated temperature and superatmospheric pressure in a heating coil and communicating reaction chamber for the purpose of materially improving its motor fuel characteristics, particularly in respect to anti-knock Value, Without excessively alring the boiling range of gasoline constitutents thereof, the vaporous and residual conversion products separated, the vapors subjected to fractionation for the removal of their insufficiently converted high boiling fractions which are condensed as reflux condensate, fractionated vapors of the desired endboiling point subjected to condensation and the resulting distillate and gas collected, the improvement which comprises commingling said reflux condensate and said high-boiling residual components and subjecting them to fractionation together for the separation of lighter constituents in vaporous form, and commingling the heavier constituents unvaporized in said fractionation With the heated oil from the heating coil, prior to the separation of vaporous and residual con- Version products, whereby said heavier constituents are subjected to somewhat milder conversion conditions than those employed in the heating coil.

Y WILLIAM F. MOORE. 

